The military has, at times, munitions which are either becoming obsolete or are in excess of the quantity desired to be kept in reserve. Various demilitarization programs have been established to deal with this excess and obsolescence.
A demilitarization ("demil") program has been in operation to disarm and recover the salvageable material of a quantity of M509A1 type 155MM artillery rounds loaded with M42/M46 general purpose type grenades. The present demil method includes the following steps: (1) removal of the nose plug; (2) extraction of the artillery round expulsion charge; (3) removal of the base plate; (4) opening the body of the 155MM round by mechanical (cutting) detachment of the ogive and base plate; and (5) hydraulic ejection (downloading) of the M42 or M46 grenades from the body. [This portion (steps 1 through 5) of the M509A1 demil method is not changed by the present invention.]
Each grenade is then disarmed for salvage. First, the fuze housing and the fuze slider is secured to prevent the fuze slider from moving into an armed position. Then, a 3/8 inch diameter hole is mechanically punched through the grenade casing at a point where the flange of a cone-shaped liner is attached to the interior of the casing, deforming the liner and exposing the explosive charge inside the grenade. (FIG. 2 shows an M42 grenade after a hole has been punched through the casing to expose the explosive charge and deform the liner.) The explosive charge in the grenade is then burned away in a controlled burning apparatus known as an Explosive Waste Incinerator ("EWI").
There are several disadvantages of this prior art method. None of the explosive material is salvaged. The EWI process takes a long time to burn away all of the explosive, and must be carefully controlled to minimize high order detonation explosive burning. Even the slow burning away of the explosive produces toxic fumes in the EWI which must be contained and detoxified. Thus, this prior art method contributes to high operating costs and equipment maintenance costs, and does not salvage any of the explosive material.
In conducting this prior art demil process, the present inventors realized that it would be preferable to develop a better method of removing the explosive charge from the grenade. If most of the explosive could be removed before the EWI, the removed explosive could be salvaged for use in commercial demolition charges and the EWI processing could be done at higher passthrough rates and with less toxic fumes and residue. These and other advantages of the invention will be apparent in the description which follows.